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Klumpar D.M. Möbius E. Kistler L.M. Popecki M. Hertzberg E. Crocker K. Granoff M. Tang Li Carlson C.W. McFadden J. Klecker B. Eberl F. Künneth E. Kästle H. Ertl M. Peterson W.K. Shelly E.G. Hovestadt D. 《Space Science Reviews》2001,98(1-2):197-219
The Time-of-flight Energy Angle Mass Spectrograph (TEAMS) is being flown on the FAST Small Explorer mission to measure the 3-dimensional distribution function of the major ion species present in the lower magnetosphere. The instrument is similar to time-of-flight plasma analyzer systems that have been designed and planned for flight as CODIF (COmposition and DIstribution Function analyzer) on the four European Space Agency Cluster-II spacecraft and, as ESIC (Equator-S Ion Composition instrument) on Equator-S. This instrument allows the 3-dimensional distribution functions of individual ion species to be determined within
spin period (2.5 s). Two-dimensional distributions are measured in 80 ms. These capabilities are crucial for the study of selective energization processes in the auroral regions of the magnetosphere. The design, operational characteristics, and test and calibration results for this instrument are presented. The sensor consists of a toroidal top-hat electrostatic analyzer with instantaneous acceptance of ions over 360° in polar angle. After post-acceleration of the incoming ions by up to 25 kV, a time-of-flight mass spectrograph discriminates the individual species. It has been demonstrated through calibration that the instrument can easily separate H+, He2+, He+, O+ and, for energies after post-acceleration of > 20 keV, even O2
+ molecules. On-board mass discrimination and the internal accumulation of several distinct data quantities combined with the spacecraft's flexible telemetry formatting allow for instrument data rates from 7.8 kb s–1 to 315 kb s–1 to be telemetered to ground through the FAST centralized Instrument Data Processor. 相似文献
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D.M. Klumpar 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1985,5(4):145-148
The auroral acceleration process that produces transversely accelerated ions is studied in detail using data primarily from a single auroral oval crossing of the ISIS-2 satellite at 1400 km. This data set is of significance because a special operational mode of the soft particle spectrometers allowed unusual temporal and pitch angle resolution to be obtained. We conclude that transversely accelerated ions having a sharp cutoff in pitch angle were accompanied by the emission of a VLF saucer and the simultaneous occurrence of an upstreaming electron beam. In contrast to the very flat pitch angle distribution of the ions, the highly field-aligned upstreaming electrons (well inside the loss cone) accompanying the ions seem to imply the existence of downward directed electric field parallel to B below 1400 km with net potentials in excess of 200 volts. The occurrence of such field-aligned electrons and VLF saucers in association with some transversely accelerated ions provides additional information on the acceleration process and reveals the complexity of the active flux tube. 相似文献
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